A sound is an airwave that is vibrating against the matter.
Most of the time sound waves vibrate against a matter that is a gas (air).
But sound waves can also vibrate against solids and liquids, too.
How sounds are measured
Some sounds are loud. Some are quiet. Measuring the sound’s loudness is called amplitude. Amplitude also measures how high a sound wave is traveling. The higher the sound wave travels, the louder it is.
Some sounds are high and some are low. This is called the sound’s pitch. A squeal is a high pitched sound. Growling is a low-pitched sound. The pitch of a sound depends upon how many sound waves are used to make that sound.
The more waves there are, the higher the pitch of a sound.
What is a noise
Noise is an unwanted sound. This means that some of the things you think are noises are pleasant sounds to someone else.
Really? Is that the only difference? Yes, that is the only difference between sound and noise.
Why are some sounds easier to hear
There are several reasons some sounds are easier to hear than others. Some of these reasons include:
- The closer you are to the sound, the easier it will be to hear it Some people are more sensitive to sounds than others because of
Training—some people are trained to hear things better than the average person
Damaged sensory perception in other areas—people who cannot see usually hear and smell better than people who can see
Intuition—a mom can tell when her baby is crying even if other babies are crying, too
The noise test
What are your favorite sounds? What sounds do you think are noise? Do your friends and family agree? Let’s find out.
Here is what you need:
- A computer with a PANDORA account or a CD player and a variety of music
- Bubble wrap
- Your voice and the voices of the people doing the experiment with you
- Squeaky door
- Variety of objects from around your house
- Yourself and 2 or 3 other people
- Pen and paper
Here is what you do:
- Play a variety of music using PANDORA or CDs
- Write down which types of music are your favorite and which types of music the other people prefer
- Pop the bubble wrap—how does the sound make each person feel
- Using your voices, make different sounds one at a time and record whether each of you feels the sounds are noise (unwanted) or not
- Repeat this process with a squeaky door and other objects in the house
- Fingers on a chalkboard
- Barking dog
- Water dripping
- Cracking knuckles
- Toy instruments
How many of the sounds were noise to you? To your friends?
- Using the same 2 or 3 people and yourself, sit in a circle on the floor—fairly close together.
- Take turns whispering the words “let’s go eat” so that everyone can hear
- Move farther away from each other and take turns whispering the same phrase in the same amplitude and pitch that you did before
- Could everyone still hear?
- Repeat the process moving farther apart each time until no one can hear what is being said